4.9-stable review patch. If anyone has any objections, please let me know.
------------------ From: Florian Westphal <[email protected]> commit 97772bcd56efa21d9d8976db6f205574ea602f51 upstream. When doing initial conversion to rhashtable I replaced the bucket walk with a single rhashtable_lookup_fast(). When moving to rhlist I failed to properly walk the list of identical tuples, but that is what is needed for this to work correctly. The table contains the original tuples, so the reply tuples are all distinct. We currently decide that mapping is (not) in range only based on the first entry, but in case its not we need to try the reply tuple of the next entry until we either find an in-range mapping or we checked all the entries. This bug makes nat core attempt collision resolution while it might be able to use the mapping as-is. Fixes: 870190a9ec90 ("netfilter: nat: convert nat bysrc hash to rhashtable") Reported-by: Jaco Kroon <[email protected]> Tested-by: Jaco Kroon <[email protected]> Signed-off-by: Florian Westphal <[email protected]> Signed-off-by: Pablo Neira Ayuso <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- net/netfilter/nf_nat_core.c | 17 +++++++++-------- 1 file changed, 9 insertions(+), 8 deletions(-) --- a/net/netfilter/nf_nat_core.c +++ b/net/netfilter/nf_nat_core.c @@ -225,20 +225,21 @@ find_appropriate_src(struct net *net, .tuple = tuple, .zone = zone }; - struct rhlist_head *hl; + struct rhlist_head *hl, *h; hl = rhltable_lookup(&nf_nat_bysource_table, &key, nf_nat_bysource_params); - if (!hl) - return 0; - ct = container_of(hl, typeof(*ct), nat_bysource); + rhl_for_each_entry_rcu(ct, h, hl, nat_bysource) { + nf_ct_invert_tuplepr(result, + &ct->tuplehash[IP_CT_DIR_REPLY].tuple); + result->dst = tuple->dst; - nf_ct_invert_tuplepr(result, - &ct->tuplehash[IP_CT_DIR_REPLY].tuple); - result->dst = tuple->dst; + if (in_range(l3proto, l4proto, result, range)) + return 1; + } - return in_range(l3proto, l4proto, result, range); + return 0; } /* For [FUTURE] fragmentation handling, we want the least-used
